Pipelines 2024: Multidiscipline

This study delves into the transformative potential of Smart Water Network (SWN) technologies and their pivotal role in mitigating water main breaks and leaks. A smart utility approach emerges as a tool in managing pressure and flow dynamics within distribution systems by integrating real-time data from sensors with advanced information and communication technologies. The project, sponsored by the Water Research Foundation (WRF), recently culminated in SWN pilots across a spectrum of utility sizes. These case studies, conducted in both large and small utilities, not only validated the efficacy of SWN technologies, but also provided a wealth of invaluable lessons and insights. This paper will highlight detailed case studies from four utilities involved in the WRF project, namely, the City of Lakewood, California; the Water and Wastewater Authority of Wilson County, Tennessee; Sydney Water in Sydney, Australia; and the Water Corporation of Western Australia in Perth, Australia.

Engineers and construction supervisors provided corrosion construction supervision and direct labor during the installation of multiple cathodic protection (CP) systems for several kilometers of gas transmission and distribution pipelines across the Province of Saskatchewan. The scope of work included the supply and installation of 84 vertical semi-deep (less than 50 ft) cathodic protection ground beds at 27 sites across Saskatchewan. Labor, equipment, sub-contractors, and materials were supplied to install the semi-deep ground beds. The purpose and objectives of the project were as follows: (1) To perform preventive maintenance (upgrade/replacement) of existing aging ground beds to ensure continuous and uninterrupted operation of the impressed current cathodic protection (ICCP) systems. (2) To prevent unexpected ground bed failure due to complete consumption of the ground bed anode material. (3) To relocate an ICCP system to a road allowance to ensure that the ground bed is not disturbed due to vehicular movement or traffic over the existing ground bed, which could subsequently lead to the ground bed’s failure. (4) To install new ICCP systems on new pipelines to provide cathodic protection on the subject pipelines. (5) To ensure improved soil-side corrosion control on the respective assets due to improved ICCP systems operation. The team reviewed Issued For Construction (IFC) documents and executed all construction work in accordance with the IFC documents and client specifications. The team reviewed project documentation to determine whether any changes could be implemented without affecting project quality and identified trade-offs in material selection and construction procedures that resulted in reduced material cost and ensured that construction was completed within schedule.

Utilities are facing increasing pressures in operating and maintaining their collection and treatment systems, leading to digital solutions to assist with optimization. Smart sewers are collection systems with remote sensors that relay level and flow information, often with cloud-based machine learning to provide insights into the behavior of the sewers. This paper focuses on a solution that provides a dashboard for smart sensors and machine learning to provide insights into the behavior of wastewater collection systems. The solution first puts “eyes on the system,” which includes pulling in data from many sources. The data are analyzed using machine learning to ascertain the behavior of the system and create alerts based on that learning. The alerts are refined over time, including alerting to blockages or impending overflows, which allows operators to proactively respond before an overflow occurs. Additionally, artificial intelligence is used in conjunction with a hydraulic model to continuously calibrate the model and make predictions of system behavior where sensors are not in place. The solution can then use forecasted rainfall to simulate and optimize control setpoints to minimize overflows and maximize catchment while not overloading the downstream wastewater treatment plant. The first case study is at United Utilities in the United Kingdom, where this solution was developed. The case study demonstrates how United Utilities has become more proactive in their response by adding sensors in their collection system, reducing spills to the environment. The second case study is in the eastern United States. The second case study demonstrates how the digital solution tool has enabled the utility to modernize maintenance approaches in their collection system to minimize overflows.

As part of the Kingston Port Modernization Design–Build Project located in area in the Bay of Kingstown on the southwest coast of the Island of St. Vincent in the Grenadines, an existing sewer outfall pipeline belonging to Central Water and Sewage Authority (CWSA) had to be decommissioned and replaced with a new sewer pipeline routed on land and offshore. The existing sewer outfall is the only wastewater effluent disposal line for the Kingston District; therefore, interruption of the service had to be kept to a minimum. To address the challenges of installing a new outfall pipe in the marine environment, the design included a new High Density Polyethylene (HDPE) pipe, hydrodynamic modeling for diffuser location, Air Release Valves (ARVs) along the new outfall, and articulated concrete mattress for stability against wave attack in the surf zone. The final design and construction resulted in a successful outfall project able to function in a marine environment.

The City of Calgary’s Nose Creek Sanitary Sewer Trunk Phase B project has been constructed over several years to accommodate future population growth and open more developable lands in northern Calgary. The project was divided into three phases, Phase A, B, and C, with each phase delivered by a separate consultant. Phase A was the downstream section of this project and was undertaken by Stantec Consulting. Phase B was the upstream section designed by CH2MHILL (now Jacobs) and further divided into different contracts (1 through 5). Phase C was a separate sewer called the Saddleridge Trunk sewer and this was designed by Associated Engineering. This paper covers Phase B, Contract 4, which had several unique challenges and included many innovative design and procurement solutions. One procurement strategy included a two-phase qualification package, with the initial phase to select a tunnelling contractor with the experience to deliver technical installations under rail and creeks, and the second phase, a request for proposal, to select a general contractor, with broader experience in open-cut and stormwater drainage, which were other aspects included within the project. This approach ensured that The City had the most qualified team available to complete the project. Technical challenges discussed in this paper include an oblique Canadian Pacific Kansas City rail and Nose Creek crossing that required independent review, and computational fluid dynamics and hydrogen sulfide modeling to confirm conditions within the trunk sewer.

The Fairbank Silverthorn Storm Trunk Sewer System (FSSTSS) will reduce the flood risk to over 4,500 properties through the construction of a main trunk storm sewer (tunnel), outfall, connection into Black Creek, a new collector sewer network (catch basins, stormwater local sewers, and stormwater trunk sewers). The main tunnel is a 4.5-m-ID segmentally lined tunnel approximately 2.4-km long ranging in depth from 7 to 45 m deep, and 1.8 km of microtunnelled sewers connecting to the main tunnel via drop shafts ranging in depth from 10 to 23 m deep. The project is located in a complex urban environment, with shafts in close proximity to homes with significant construction impacts to residents lasting up to 2 years. This paper describes the impacts and challenges of large diameter trenchless projects and associated considerations and mitigation measures put in place.

Following the closure of the Edmonton City Centre Airport in 2013, the City of Edmonton approved the redevelopment of the 536-acre Blatchford Field, with the vision transforming the Blatchford area into a leading example of sustainable development. The availability such a large unoccupied parcel within Edmonton’s downtown presents a unique opportunity to design an interconnected, sustainable, and low carbon community for over 30,000 residents. The Blatchford development’s heating, cooling, and hot water needs are to be met by an innovative district energy sharing system (DESS). This DESS interconnects all buildings within the development into a nodal network of High-Density Polyethylene (HDPE) piping, delivering ambient temperature water to hyper-efficient building-side heat pumps for heat and cooling. This innovative district energy technology allows for load sharing between buildings and is supplemented with renewable energy sourcing from a geoexchange field and a future sewer heat exchange (SHX) system. There are many novel design features in the Blatchford development that provide insight into how DESSs can be adopted efficiently and effectively to create a self-sustaining low carbon community. Blatchford can be considered a proof of concept of how this technology is not only becoming more accessible, but necessary to reduce emissions in the race to combat climate change.

A 20″ 58 km ascending Main Oil Line (MOL) transporting 28,500 m³/day of crude in Oman experienced sudden back pressure of 54 barG during routine pigging activity. The pig got stuck at 4.6 km and caused MOL to trip. It was retrieved by back-flow and found wrapped with a sticky polymerized organic substance. A novel specialty chemical technology was designed to disintegrate and disperse deposits into small, non-sticky fragments. The formulation was engineered to be an aqueous base to travel at the bottom part of the crude and to prevent any massive dilution. A non-corrosive chemical pill was injected into the pipeline from the inlet to provide a plug flow and pushed by a medium-density foam pig (online). Different flow rates were maintained to focus on the target location to allow maximum soaking/contact time. The foam pig was received at the receiver end, pushing all debris out, and leaving the MOL cleaned. The entire operation was performed online except for a short time of 2 h, which was utilized to inject the specialty formulation from the launcher section.

Evidence associated with unaccounted macro dynamic effects influencing friction losses in large diameter cross-country liquid pipelines is examined with emphasis on back-calculated friction factors. Considerable amount of operating data is used to develop a simplified equation to estimate more realistic globally measured friction factor correspondent to the theoretical Darcy–Weisbach friction factor. This equation accounts for the summed effects of laminar sublayer, boundary roughness on the fluid profile plus, others cumulative and unaccounted macro dynamic effects normally occurring in curved pipes and in real-world cross-country liquid pipelines. The model has been developed and lately verified with reliable operating data from large crude and water cross country pipeline systems operating at large Reynolds numbers (10⁴ < Re < 10⁷) and covering a wide range of kinematic viscosity (1 cP < υ < 590 cP). Also, potential internal roughness growth, due to deposits and fouling, can be considered. The explicit equation was achieved by identifying a Karman–Prandtl type multiplier function and linked to the back-calculated global friction factors using the least squares technique with obtained coefficients of determination (R²) higher than 0.91, indicating the high reliability of the proposed method.

Studies investigated the behavior of pipeline steel in hydrogen environment but presenting the natural gas pipeline network as a viable solution for hydrogen transportation is still debatable. The current review presents the evaluation of the available research on the hydrogen-induced degradation of pipeline steel. The hydrogen-induced degradation of pipeline steels under electrochemical charging and/or exposure to hydrogen gas can be attributed to variables, namely, gas composition, hydrogen pressure, loading conditions, temperature variations, welding type, and technique and the inhibitors used. Given the outcomes, it can be inferred that the current pipeline infrastructure can present a viable and cost-effective option for blending hydrogen in existing natural gas pipelines. However, it is highly suggested that future researchers ought to prioritize the investigation of fatigue behavior about parental cracks and dents, gouge development, corrosion effects, as well as weldments with various flaws.

Many gas and liquid pipelines traverse unstable landscapes, such as waterways, floodplains, and steep terrain. These unstable landscapes often pose threats to pipeline stability and integrity. A variety of approaches are available to better understand and predict the magnitude and frequency of natural forces (geohazards) that threaten pipeline integrity. Risks of pipeline failures from these threats are of high concern to the industry, and the risks escalate significantly in high consequence areas. One approach is to prioritize vulnerable pipelines by assessing and prioritizing them through a combination of publicly available data, operator knowledge, and site-specific information (e.g., pipeline characteristics, recent survey data, etc.). The objective is for hydrologists, geologists, engineers, and environmental scientists to evaluate potential failure risk for those pipelines for which a refined understanding of vulnerability is desired. Depending on the results/outputs of a pipeline natural forces assessment, it may then be critical to understand requirements to permit, design, and implement recommended actions to minimize potential risk at pipeline segments of concern—through monitoring plans, operational controls, and/or engineering controls.

The structural analysis of buried pipelines largely depends on the circumferential soil pressure distribution around the pipe, as the lateral and axial soil resistances are a function of the soil overburden load. In the current industry practice, the pipe–soil interaction is represented using three orthogonal springs where the soil resistance is defined using the design guidelines. These guidelines were primarily developed based on steel pipelines. However, the effect of circumferential soil pressure distribution around medium-density polyethylene (MDPE) pipe, and thereby, the soil resistance to the pipeline can be very different as the soil load depends on the pipe’s relative stiffness and the soil’s shear strength parameters. The normal stress on the pipe surface, applied during conventional beam-on-spring analysis, is influenced by the pipe–soil interaction, which should be accounted for properly evaluating the pipe performance. This study investigates the normal stress on the pipe surface for buried MDPE pipe bend using finite element (FE) analysis. Plane strain analysis is used to investigate the stresses within the straight portion of the pipe, and three-dimensional analysis is performed to examine the stresses near the bend. Comparisons are shown for the FE analysis of straight pipe, pipe bend, and plane strain analysis results. It is seen that plasticity develops due to the presence of a stiffer element (pipe) in the soil medium, which may affect the soil stress distribution and, thus, the pipeline stress response. A pipe bend with a stress intensification factor and flexibility factor equal to one is assumed to behave similar to a straight pipe. This study shows that the soil stress around a bend and straight pipe differs. The effect of pipe presence in soil on the calculation of stress increase due to surface load is also shown in this study. A conceptual methodology is proposed to use a shell-spring-based finite element model to investigate the pipe stress due to traffic load. Using the normal soil stress distribution around a pipe, the in situ stress is idealized from the 2D plane strain or 3D continuum model. This in situ stress around the pipe is applied to the shell model. Then, the stress increased due to a traffic load using the Boussinesq theory is calculated and applied to the shell model in the next analysis step. The soil resistance is idealized based on American Lifelines Alliance (ALA) design guideline spring.

Recent developments in remote inline inspection (ILI) tool-tracking technology have improved the safety of ILI projects by eliminating the need for field technicians to travel to site to witness tool passages. This is particularly advantageous when tracking overnight and through overly difficult to access terrain. One such development is permanent remote ILI tracking. A permanent remote tracking system consists of a series of permanently installed above ground markers (AGMs) that are strategically located to ensure full tracking coverage and monitored 24/7. This paper will explore that the innovative approach PureHM’s partner, Enbridge, has taken to mitigate risk via the installation of a permanent remote tracking system on their Athabasca pipeline network, driving a cost saving of over $4,000,000 over the duration of the 6-year program.

In 2023, PureHM conducted an emergency inline acoustic leak detection and threat monitoring survey on approximately 9 km (6 mi) of 200-mm (8-in.) carbon steel pipeline that transports crude oil. The operator observed a deviation on their continuous pipeline monitoring (CPM) system, conducted a stand up, and subsequently suspected a leak along this segment. Conventional leak detection methods were unable to pinpoint the location of the suspected leak, and subsequently, the line was purged. Following the purge, PureHM mobilized for an emergency acoustic leak detection and threat monitoring survey. As the leak detection tool required a liquid medium to detect leaks, PureHM collaborated with the operator to prepare a water slug that would function as a carrier for the tool while also providing the liquid medium. The water slug was contained on both ends by cleaning pigs, with the leak detection tool positioned approximately in the middle. The slug and tools were inserted into the pipeline through a standard launcher, traversed the line using nitrogen to push the tool, and were extracted from the pipeline through a standard pig trap. The survey identified three (3) leaks within a 30-m (100-ft) section of the pipeline. The identification of the three (3) leaks allowed the operator to swiftly enact risk mitigation and repair protocols. This paper will detail the process of the inline leak detection survey, the operational challenges and solutions encountered, and implications for future use of leak detection tools in lines without a liquid medium.

Machine Learning (ML) applications in pipeline failure risk prediction have recently shown promising results. However, obtaining actual data to train ML models is a significant challenge due to safety concerns. To overcome this limitation, this study employed a Generative Adversarial Network (GAN)-based framework to generate synthetic data based on a subset of experimental test data compiled from the literature. The burst failure risk of corroded oil and gas pipelines was determined using probabilistic approaches where pipelines were classified into two groups: (1) low risk (pf: 0−0.5) and (2) high risk (pf: >0.5). Two Random Forest (RF) models were trained and validated using a subset (70%) of actual experimental data and combined actual and synthetic data. The outcomes of this study revealed that synthetically generated data improve the accuracy of ML models and could be an alternative to actual data for developing failure risk prediction without compromising the safety of real data.

Corrosion is identified as a primary factor contributing to a major fraction of crude oil pipeline failures. The internal surfaces of crude oil pipelines experience prolonged exposure to corrosion-causing species with brine as a significant contributing factor to corrosion. To mitigate internal corrosion in steel pipelines, corrosion inhibitors are employed, which are only effective in certain circumstances. Moreover, these corrosion inhibitors are expensive and toxic which can damage the environment. This study explores the use of bio-based erythritol, a four-carbon, four-hydroxyl sugar polyol derived from corn starch, as a potential corrosion inhibitor to mitigate chloride-induced corrosion in pipelines. Erythritol has shown a strong affinity to adsorb itself onto the steel surface and block the active corrosion sites in an aggressive chloride environment. A simulant of crude oil is prepared by taking 25% brine (23% NaCl), 75% corn oil, and 3% soy-lecithin as an emulsifier. To determine the corrosion inhibition efficiency of erythritol, various brine-in-corn-oil emulsions are prepared by incorporating 0%, 1%, 2%, and 3% of erythritol. Accelerated corrosion tests are conducted to visually monitor the corrosion damage on steel specimens, and potentiodynamic polarization tests were used to quantify the corrosion current densities and corrosion rates of steel specimens, subjected to emulsions containing various concentrations of erythritol. The qualitative and quantitative results indicate that erythritol is a promising candidate for corrosion inhibition in crude oil pipelines.

During the construction of Coastal GasLink (CGL) through the town of Kitimat, BC, the Project encountered sensitive glaciomarine clay (GMC) that extended up to 40 m in depth along the pipeline right-of-way. While sheet piling is a common solution utilized to stabilize otherwise unstable trench wall conditions, cantilever sheet piles rely on competent soil at depth for toe resistance which provides the lateral support required for safe trench excavation. Due to the significant depth of the GMC, the lack of toe resistance severely limited the capacity of any installed sheets regardless of the steel section utilized. Reinforcing the entire length of cantilever sheet pile wall (SPW) trench with structural cross-bracing was not a suitable alternative for the soft GMC area due to interference with pipe installation sequences and project schedule implications. To meet regulatory pipeline installation requirements and successfully construct through this sensitive area, the Project utilized a combination of shallow trench and soil mounding construction to successfully install the pipeline, minimizing the need for cross trench bracing to short sections only at watercourse crossings, where the pipe had to be deeper. A robust field monitoring program was also implemented to ensure that construction was completed within the predicted bounds of a finite element soil model, which was calibrated with deflection limits that considered the sensitive nature of the GMC.

The presence of defects in polyethylene (PE) pipes for natural gas transport can lead to catastrophic failures given the flammable nature of the accident. Third party damage to the external surface of pipeline is among the most common reasons for pipeline failure. In addition, the presence of manufacturing defects on the internal surface of pipeline can result to internal crack growth during pipeline operation. This paper attempts to expand the scope of guided-wave Ultrasonic Testing (UT) to detect both external and internal cracks in a PE pipe, because in its current state, UT is mostly restricted to long range inspection in steel pipes. A laboratory setup is assembled for wave-based monitoring of pipes in controlled damage conditions. The preliminary results demonstrated the potential of UT for detection of both types of cracks, and the findings are used to develop a numerical model which can be later be used to investigate a wide variety of pipeline defects. The outcome of this study establishes the potential of UT to detect both external and internal cracks in PE pipes.

The City of Miami Beach, FL, has 28 aerial water/sewer mains located along Florida’s oldest causeway, the Venetian Causeway, which links the City of Miami, FL, to the island City of Miami Beach, FL. The corridor consists of 10 islands connected via 10 bridges in Biscayne Bay, one of Florida’s most protected water bodies. These aerially supported pipelines were determined to be at risk having experienced higher occurrence of failures compared to buried pipelines in the City’s system. This is likely due to their exposure to the corrosive marine environment and from additional stresses from wind loading and wave action from the ever-growing risk of named storm events. In response to pipeline failures and to provide greater long-term reliability, the City of Miami Beach accelerated design and construction of buried replacement pipelines on an emergency basis. Exacerbating the challenge was Miami Dade County’s plan to replace the 1920s era bridges, requiring relocation of the water and sewer mains. The timing of the future bridge construction and the increasing service life risk to the existing pipelines led to the need to find an alternative buried solution. An additional challenge to finding a buried pipeline corridor was Florida’s property laws where private property often extends to underwater lands, thus restricting the available corridor to the existing roadway easement. Environmental restrictions prevented dredged and coffered installations from being viable and ultimately drove alternative evaluation to pursue trenchless options. Alternative analysis evaluated several trenchless installation methods, including microtunneling and deep tunnel alternatives. These options were excluded due to the significant costs and construction time. Ultimately, the study process selected Horizontal Directional Drilling (HDD). The challenge was that, due to the extremely tight and obstructed available corridor, pipeline installation by HDD methods required steering accuracy near the limits of feasibility to meet all project constraints. Therefore, performance specifications for accuracy, both steering, and final as built location were required as part of the design as well as careful coordination the County’s replacement bridge design team to avoid conflicts with future bridge support systems. HDD pipeline design included performance specifications for two primary elements: for acceptance criteria of alignments through the use of specific critical alignment locations indicated in the contract documents at the highest risk locations and for the specific type of as-built survey system with capabilities to survey to an accuracy level high enough to verify that the final pipe locations. Historically, when limit-pushing technologies have been applied under complex conditions, risk sharing techniques have often been included within construction contracts to fairly mitigate and balance risk between the parties best suited to control the risk. With this project pushing the limits of steering guidance and as-built survey technology, risk sharing methods were evaluated and developed to improve the potential for project success.

The construction of the Coastal GasLink (“CGL”) Pipeline encountered a multitude of steep slopes, primarily in the high-altitude sections within the Coastal Mountains near Kitimat, BC. Steep slope pipeline construction offers unique design, safety, and constructability challenges. Varying installation methodologies were utilized by CGL, including the application of a mining technique referred to as a Raise Bore. A Raise Bore is a trenchless installation method consisting of a near-vertical bored section and a horizontal blasted drift tunnel where the pipeline can be installed. This technology has been used extensively in the mining industry and TC Energy utilized this method to install a section of pipe on a previous project in Mexico. The use of a Raise Bore on CGL was the first of its kind for pipeline construction in Canada. This paper discusses the benefits and challenges associated with the implementation of a Raise Bore, as well as the design inputs, execution, risk analysis, and lessons learned from the CGL Project.

The community of Sunnyside in Calgary, Alberta, is partially located within the Bow River floodplain. Sunnyside is protected from river flooding by an existing earth berm. The berm also prevents storm flows from being conveyed overland into the Bow River. Following a flood in 2013, the City of Calgary engaged Associated Engineering to complete a drainage study. It examined the drainage system within the community and recommended several drainage improvements. One of the improvements identified was a separate storm trunk to convey storm runoff by gravity, using an inverted siphon, from the Upper Plateau area directly to the Bow River. This new stormwater trunk intends to reduce the risk of stormwater surcharging in Sunnyside during elevated and low river level events on the Bow River. The proposed trunk, together with other improvements, reduces the risk and magnitude of overland flows, due to extreme rainfall events, from entering the community.

A range of cyber attacks on oil and natural gas infrastructure have occurred over the past decade showing a range of capability and potential impact across critical infrastructure. These attacks showcase the potential of adversaries to disrupt the delivery of oil and gas products, highlighting the need for enhanced cyber risk management across oil and gas infrastructure networks. Since the Colonial Pipeline cyber attack in May of 2021, the Department of Homeland Security’s (DHS) Transportation Security Administration (TSA) has provided and updated several security directives regarding physical and cyber security for pipeline and rail systems, driving the need to measure baseline and improvements to cybersecurity performance. In order to implement a comprehensive approach to cybersecurity, an owner or operator must first measure their baseline vulnerabilities and risks, develop a set of cybersecurity controls and metrics, and regularly measure the implementation, effectiveness, and impact of controls. This paper will discuss cybersecurity performance metrics and methods for measuring and managing cybersecurity performance for pipeline owners and operators.

Understanding the pipe–soil interaction effects at the pipe–soil interface of a buried pipeline is needed to estimate the stresses and strains on the pipeline subjected to longitudinal transient and permanent ground displacements during a seismic event. In general, pipe–soil interaction effects would be dependent on the actual displacement pattern, pipe–soil interface behavior, configuration of the pipe segments as well as joints, and available axial flexibility within pipe joints. In buried pipelines with uniform pipe barrels, such as in most continuous pipeline situations, axial resistance is primarily contributed by frictional and adhesive behaviors of the pipe–soil interface. However, in certain situations of continuous pipelines (e.g., flanged joints) and in segmented pipelines (e.g., bell- and spigot-type configurations), pipeline cross sections are typically larger than the regular pipeline barrel cross sections. Due to these configurations, the axial resistance in a pipe barrel does not develop solely from pure axial frictional and/or adhesive resistance on the pipe–soil interface. A bearing type resistance (e.g., passive resistance at the enlarged joints) would also be contributing to the axial resistance of the pipe. It should be noted that the maximum passive resistance that could be developed on the pipeline joint is also a function of the relative movement at the pipe–soil interface. While underestimating axial resistance for traditional non-seismic situations mostly yield conservative designs, such is not the case for seismic design conditions. Especially important is the axial resistance contribution in estimating the connection force demand arising from potential seismic hazards acting on a pipeline. Recognizing the importance of accurate estimation of the axial force connection demand on a buried pipeline from a design seismic hazard, a critical review of the approaches to estimate the axial resistance on a pipeline has been completed. This paper presents a summary of the current practice to estimate maximum axial resistance in a buried pipeline, critical review of the resistance components contributing to the axial resistance, and a proposed analytical approach to estimate the maximum axial resistance on a continuous or segmented pipeline with enlarged joints.

The Foundry Branch, traversing Glover Park in northwest Washington, DC, has historically been a picturesque creek, but recent climate change-induced record rainfall has transformed it into a volatile waterway, exacerbating the risk of Sanitary Sewer Overflows (SSOs) at a crucial crossing. This crossing, where an encased sanitary sewer on shallow piers discharges into a 27-in. interceptor, has experienced significant SSO events, prompting DC Water to initiate a Capital Improvement Project (CIP) aimed at a comprehensive overhaul. The project encompasses not only the replacement of the existing sewer crossing but also enhancements to the receiving sanitary trunk sewer, marking a significant undertaking within a wetland area with complex permitting processes involving the National Park Service (NPS), the District Department of Energy & Environment (DOEE), and the US Army Corps of Engineers (USACE). Estimated to span 4−5 years from design inception to construction completion, this initiative underscores the challenges posed by environmental regulations and climate change alike. In response to two SSO incidents within an 8-month span in 2022 and 2023, DC Water conducted a geo-structural evaluation of the creek crossing and engaged Spiniello Companies for a site assessment, uncovering significant upstream infiltration. Through collaborative discussions with NPS, DOEE, and USACE, DC Water devised an emergency work plan, earning the requisite approvals for immediate intervention. This plan included the removal of obstructive vegetation, the creation of an access route within the dense woodland, and the demolition of the existing crossing to make way for an innovative solution. The implemented design features a 12-in. PVC sewer line, supported by helical anchors and set at a 2% slope, encased to ensure durability. This new crossing, adorned with a stepping stone surface per NPS request, serves dual functions as both a sewer conduit and a pedestrian pathway. Further, the design integrates flowable fill encasement for the sewer segment and a concrete headwall on piles at the creek crossing, significantly bolstering the embankment erosion resistance. In presenting this resilient infrastructure solution, DC Water aims to showcase how engineering innovation can effectively mitigate the impacts of climate change on urban water management systems. The project not only addresses immediate SSO concerns but also sets a precedent for future-proofing critical infrastructure in environmentally sensitive areas. By employing an oversized sewer crossing on erosion-resistant piles and installing an upstream monolithic manhole with a watertight frame and cover, DC Water demonstrates a commitment to safeguarding the community and the environment against the challenges of the coming decades.

The Spring Hill Sewer Separation and Streetscapes Phase 1 project, located in Somerville, MA, was initially programmed as a straightforward sewer separation project. It is one of the five key projects in the City of Somerville’s Union Square Stormwater Mitigation Program designed to reduce the risk associated with aging infrastructure, solve existing system deficiencies, achieve regulatory compliance, and create system capacity to accommodate planned development. The underground challenges of separating 65 acres of 100-year-old combined sewers cause a significant impact on a residential neighborhood. Recognizing this early, the City pushed to incorporate many multi-departmental goals, including green stormwater infrastructure, renewal of an aging water distribution system, safer streets through multi-modal infrastructure improvements, increase to the urban forest canopy, as well as critical third party utility upgrades. By starting the community engagement and inter-departmental coordination process early in the planning phase of a project and returning to that coordination at multiple junctures throughout design and construction, the City of Somerville was able to achieve the initial goal of the project to remove clean stormwater from the combined sewer system and mitigate downstream flooding in Union Square while also achieving many of the aforementioned City goals within the neighborhood.

As a large regional utility agency, the Trinity River Authority of Texas has a capital improvement program that spends hundreds of millions of dollars each year in treatment plant and large diameter pipeline construction projects. For this work, the Authority uses numerous engineering consultants and construction companies to design and construct these projects. As such, what can be learned from the design and construction, especially for situations that repeatedly occur from project to project? This paper will present issues and situations that are regularly and frequently found, as well as guidelines and best practices to use to improve project quality and schedules. Included in this paper will be materials, equipment, and procedures that are sometimes are misunderstood in their use and applications, together with practical recommendations for their engagement. In addition, this paper will examine legal issues and construction law topics that are common to pipeline projects, as well as suggested protocols in the course of a project.

The York Durham Sewage System (YDSS) was originally built in the 1980s as a single forcemain by the Province of Ontario and its ownership was subsequently transferred to the Regional Municipality of York in the 1990s. Local sewer systems throughout the Town of Newmarket (located in York Region) connect to the YDSS which then conveys effluent to the Duffin Creek treatment plant located approximately 60 kilometers (km) to the south. In 2016, York Region’s water and wastewater master plan identified that the YDSS was reaching capacity in the Town of Newmarket and required an upgrade. The resulting forcemain twinning project included the addition of a secondary forcemain. This upgrade was challenging as the new forcemain had to be installed through a dense urban environment and a floodplain of the East Holland River which runs north to south through Newmarket. Microtunneling installation of the 5.5 km long forcemain through Newmarket required 11 river crossings, 3 railway crossings, numerous street crossings, and work within and below city parks. The forcemain was installed in two passes. For the first pass, full face slurry microtunnel boring machines (MTBM) were used to install precast microtunnel pipe (casing pipe), manufactured to CAN/CSA A257.2 (ASTM C76). For the second pass, AWWA C301(E) prestressed concrete cylinder pipe (PCCP) was used as the carrier pipe and was installed and grouted in place within the casing pipe.

The New Braunfels Utilities Surface Water Treatment Plant Discharge Water Line is a 30-in./24-in. diameter potable water distribution line that required a 413 LF trenchless installation beneath the Guadalupe River. This installation had tight alignment tolerances, was beneath a river with highly incised embankment conditions and a 20-ft surface elevation difference between shaft locations, was next to an active pump station, and had inconsistent subsurface ground conditions. Three installation methods were considered: Horizontal Auger Boring, Horizontal Directional Drilling, and Vertical-curved Microtunneling. The project team selected the vertical-curved microtunnel method which reduced risk and allowed for an optimized alignment compared to other methods. Ultimately, it was utilized in a successful installation that satisfied all parties.

China is unique in that it does not adopt a traditional engineering consultancy model employed in most countries where private design firms are employed to design and develop solutions to infrastructure needs. Instead, design is conducted through government-operated “Design Institutes” located in each of the 34 Provinces and Autonomous Regions. Graduating engineers are employed by these Institutes and work in various areas, including water and wastewater pipelines. To further improve and support the Design Institutes, the Infrastructure Hospital concept was first initiated in 2015 where a centralized research facility for infrastructure R&D was envisioned in Henan Province. The concept is to “diagnose” and recommend solutions for owners looking at addressing their infrastructure renewal, rehabilitation, and new construction needs. The plan involved establishing smaller “Clinics” in various cities throughout China. To date, more than 76 smaller Clinics have been established across the country. Each Clinic can assist with basic inquiries regarding solutions for infrastructure projects from local governments. More difficult projects are elevated to the Infrastructure Hospital for further evaluation, which may involve lab or field testing prior to implementation. Additionally, should a new product be introduced, then it could be tested and evaluated at the Infrastructure Hospital and given a government certificate of approval for application in China. The Infrastructure Hospital is an integrated facility that was completed in 2022 and includes indoor and outdoor laboratory facilities to conduct research and testing on all aspects of infrastructure. For pipeline-related research, there is currently a 10 km test loop set up for testing water pipelines, an underground facility to evaluate various tunnel lining approaches, a sewer pipe network to evaluate various rehabilitation material options, and two tunnel boring machines for researching more efficient installation practices. The Infrastructure Hospital is being used by academic researchers from various universities in China conducting pipeline and other infrastructure research. It is anticipated that international researchers and companies will make use of the Infrastructure Hospital as an incubator for new and innovative technology solutions. This paper presents the historical background and discusses several research projects conducted at the facility that have positively impacted the municipal pipeline industry.